The herein disclosed and taught invention generally relates to a cyclic operating tool employing an energized flywheel to provide the necessary energy to perform a working cycle.
More specifically the invention disclosed herein relates to, but is not necessarily limited to, a hand held electromechanical fastener driving tool, such as a fastener driving tool having an electrically powered motor energizing a flywheel which provides the necessary kinetic energy to drive a fastener into a work piece. The electrical power may be provided by either a battery or an AC electrical power source.
In the past, where relatively large energy impulses have been required to operate a fastener driving tool, such as an industrial nailer or stapler, it has been a common practice to power such tools pneumatically or by a corded electric motor. Such tools are capable of driving a 3xe2x80x3 or longer nail, or staple, into framing wood such as 2xc3x974s, for example.
However, pneumatic driving tools require an on-site air compressor, and corded electric tools require an on-site source of electrical power. Further both type of tools require the user to drag a pneumatic or electrical umbilical behind them during use. Dragging such an umbilical behind becomes particularly troublesome when working in high places such as upon a roof or a ladder.
Electrically driven tools, such as solenoid operated fastener driving tools, are also well known. These are primarily used in lighter duty applications such as in driving one inch brad nails, for example, rather than the larger 1.25 to 2.5, 15 gauge finishing nails and/or heavier framing nails.
Also much effort has been expended in the prior art for providing a heavy duty, high powered, fastener driving tool employing a flywheel as a means to deliver kinetic energy sufficient to power a heavy duty fastener driver. Examples of such systems are disclosed in U.S. Pat. Nos. 4,042,036; 4,121,745; 4,204,622, 4,298,072 and 5,511,715. However, the referenced prior art requires the use of corded electric motors to provide the energy necessary to energize the flywheels.
The present invention discloses and teaches a novel drive mechanism particularly useful in a cyclic hand tool, which has an operative work cycle followed by a reset cycle such as a powered nailing machine. More particularly the present invention is useful in a cyclic tool employing the kinetic energy of an energized flywheel to provide the necessary energy to perform the tool""s operative working cycle.
A drive mechanism is taught whereby a first pair of rotatable caming plates, activated by an electrical solenoid, cause a clutch assembly to engage an energized flywheel. Upon engagement of the flywheel by the clutch a second pair of rotatable caming plates, activated by the flywheel, affect the compression of a spring whereby additional force is imposed upon the clutch ensuring slip free engagement during the following operative work cycle of the drive mechanism. Upon completion of the mechanism""s operative work cycle, the second pair of caming plates affect a rapid disengagement of the clutch from the flywheel whereby the drive mechanism returns to its start position and the flywheel dissipates its remaining energy by free wheeling until it stops or until it is re-energized for an additional work cycle.
Although the following embodiment describes the present invention as used in a hand held, battery powered, nailing machine, it is to be understood that the invention may also be used in a corded electric motor embodiment. Further it is to be understood that the present invention is also suitable for applications, other than hand held tools, where a cyclic operation, similar to that of a hand held nailing machine, is desired.